Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenues	$ 433	$ 351	$ 1,459	$ 2,883
Operating expenses:
Research and development	4,887	6,881	10,291	14,837
General and administrative	2,827	2,302	5,437	4,633
Settlement costs (Note 9)	(709)		(667)
Operating Expenses, Total	7,005	9,183	15,061	19,470
Loss from operations	(6,572)	(8,832)	(13,602)	(16,587)
Other income (expense), net:
Interest expense, net	(549)	(530)	(1,042)	(1,081)
Change in fair value of PIPE Warrant liability	11,125	(23,925)	9,660	(24,409)
Other income (expense), net	10,576	(24,455)	8,618	(25,490)
Income (loss) before provision for income taxes	4,004	(33,287)	(4,984)	(42,077)
Provision for income taxes				(50)
Net income (loss)	$ 4,004	$ (33,287)	$ (4,984)	$ (42,127)
Basic net income (loss) per share
Net income (loss) per share	$ 0.03	$ (0.30)	$ (0.04)	$ (0.45)
Weighted average number of common shares outstanding	118,940	110,550	118,891	93,493
Diluted net income (loss) per share
Net income (loss) per share	$ (0.06)	$ (0.30)	$ (0.11)	$ (0.45)
Weighted average number of common shares and dilutive common share equivalents outstanding	128,692	110,550	129,372	93,493
Collaboration and Licensing Revenue
Revenues:
Revenues	$ 336	$ 351	$ 1,316	$ 2,883
Partnership Royalties
Revenues:
Revenues	$ 97		$ 143